Two weeks ago I posted the trailer for physicist Clifford Johnson’s short movie entitled Shine A Light, and now his science film is viewable online! In his own words:
As I said before, this short film is (I hope) fun, engaging, and informative. I hope lots of people take the time to watch it at least a couple of times. A basic scientific knowledge of the world is for everyone. Science is part of our culture and should be more widely circulated. Films such as this is one of the ways the National Science Foundation, who provided the support to make it, is helping to bring science to everyone. For this (and the other ones in the series) to be a success, your help is needed. It needs to be seen. Tell your family and friends, colleagues and students, local teachers, etc., about it. Forward it on to people you know. Blog it, tweet it, facebook share it, etc. Crucially, remember that it is designed to be not just for people who already know they have an interest in science, but others too, so make no assumptions about who might like it… just please send it. Thanks.
So with that introduction, let’s take a look…
August 18th, 2009 at 4:15 pm
I like it. Makes me miss Bill Nye.
Still, I kind of pictured the process as being less of an orbit dance around the nucleus, and more of a weird sci-fi mosh pit, what with the whole particle/wave thing.
August 18th, 2009 at 6:23 pm
Feynman was first with the “dancing” electrons and photons. E.g., p. 17 of his book QED, Penguin Books edition, 1985:
“The photon and electrons do some kind of dance…”
Professor Johnson’s movie is nice though. Benjamin, take a look at Chapter 3 of Feynman’s book QED, specially pages 84-5 of the Penguin edition. There’s nothing strange in the wave-particle duality manifested by fundamental particles when they move through small spaces like the orbits in atoms or the small gaps in the double slit experiment. The wave type diffraction and indeterminancy arise because the electromagnetic field of the electrons in the slit edges and binding the electrons to nuclei are not classical fields, but are quantum fields. Field quanta randomly get exchanged between charges to cause the Coulomb force which binds electrons in atoms, so it’s chaotic (like Brownian motion where air molecules are randomly bombarding dust particles, inducing chaotic motions into the orbits of electrons which would otherwise be elliptical). A photon of light similarly is a quantum of electromagnetic energy, so it interacts with the random field quanta from the electrons that it passes near to. This is why light goes slower in glass than in vacuum, and why small slits cause it to diffract in a random way. If the slits are close enough that the transverse sie of the photon overlaps them, then both slits influence the motion, as Feynman explains by applying path integrals to the double slit experiment in his QED book, p. 85:
“… when the space through which a photon moves becomes too small (such as the tiny holes in the screen) … there are interferences created by two holes .. The same situation exists with electrons: when seen on a large scale, they travel like particles, on definite paths. But on a small scale, such as inside an atom, the space is so small that there is no main path … there are all sorts of ways the electron could go, each with an amplitude.”
August 19th, 2009 at 1:22 am
Thanks Nigel! I’ll add it to the pile of summer reading.
September 14th, 2009 at 1:00 pm
[...] month I posted Shine A Light, and now Clifford’s second short film Laser has debuted on the interwebs! Take a look and [...]